Pipelike muffler with zigzag shape

ABSTRACT

One pair of straplike sidewalls are zigzag bent so that flat sidewall members thereof meet at an acute angle. A second pair of flat sidewalls are secured to opposite edges of the first pair of walls to define a zigzag tortuous passage which is equipped at its opposite ends with tubular adapters. The zigzag bent walls of the first pair may be compressed or extended so as to preposition their wall members at a selected acute angle before the second pair of sidewalls are secured thereto.

United States Patent Inventor Horace A. Wright lmmokalee, Fla.

Appl No. 33,362

Filed Apr. 30, 1970 Patented July 20, 1971 Assignee William H. Doub lmmokalee, Fla.

8 part interest PIPELIKE MUFFLER WITH ZIGZAG SHAPE 5 Claims, 4 Drawing Figs.

U.S. CL 181/70, 181/36 B, 181/61 Int. Cl FOln l/08 FieldofSearch 181/61- [56] References Cited FOREIGN PATENTS 210,488 2/1924 Great Britain 181/70 376.374 7/1932 Great Britain Primary ExaminerRober1 S. Ward, Jr. Att0rneys-Munson H. Lane and Munson H. Lane, Jr.

PATENIEU JUL 20 I971 FIG FIG/l.

mvm'Tole HORACE A. WRIGHT BY Km ATTORNEY PIPELIKE MUFFLER WITH ZIGZAG SHAPE This invention; relates to new anduseful improvements in mufflers or exhaust silencers for internal combustion engines of automobiles, trucks or other vehicles, and the principal object of the invention is to provide an improved muffler of very simple construction having good sound-attenuating characteristics and a long useful life.

As such, the muffler of the invention utilizes two pairs of sidewalls arranged so as to define a zigzag tortuous passage of a rectangular cross section, the zigzags of the passage being at an acute angle to one another so as to be progressively encountered by exhaust gas flow through the passage and produce a highly effective silencing action. Unlike in conventional mufflers where internal baffles in an enclosure are subjected to early damage by the effects of heat, the sidewalls of the muffler of the invention are fully exposed to the atmosphere and cooled by the ambient air, thus making it possible for the muffler to function effectively for a long period of time.

The simple construction involves only the two pairs of sidewalls defining the tortuous passage and two tubular adapters at the ends of the passage for installing the mufi'ler in the exhaust system. Thus the muffler may be easily and economically manufactured.

' Another important feature of the invention is that its soundattenuating properties are related to the magnitude of the angle included between adjacent zigzags of the tortuous passage, and this angle may be selected so that the muffler has sound-attenuating characteristics best suited for an engine of a given piston displacement.

' With the foregoing more important object and features in view and such other objects and features which may become apparent as this specification proceeds, the invention will be understood from the following'description taken in conjunction with the accompanying drawings, wherein like characters of reference designate like parts, and wherein:

F IG. 1 is a side elevational view, partly in vertical section,

' showing the muffler of the invention in an exhaust system;

FIG. 2 is a plan view of the muffler; 1 F IG. 3 is a vertical sectional view, taken substantially in the plane of the line 3-3 in FIG. 1; and

FIG. 4 is a side elevational view, partly in vertical section,

' showing a muffler wherein the angle included between the zigzags of the passage exceeds the angle range desirable in the invention..

Referring now to the accompanying drawings in detail, the mufi'ler in accordance with the invention is designated generally by the reference numeral in FIGS. 1 and 2. it is to be noted at this point that although the views in these figures have been identified as the side elevational view and plan view, respectively, this is only for purposes of reference. As a practical matter, the mufi'ler may be installed in the exhaust system either in a vertical or a horizontal-plane, and in the latter instance FIGS. 1 and 2 would be regarded as a plan view and side elevational view, respectively.

In either event, the mufiler 10 comprises a pair of spaced parallel sidewalls 12 and a second pair of spaced parallel sidewalls l4 which are secured, as by welding for example, to opposite edges of the sidewalls l2 and coact therewith to define a passage lS of a rectangular cross section,'as will be apparent from FIG. 3.

The first pair of sidewalls 12 are constituted by metal straps which are zigzag bent along a plurality of longitudinally spaced transverse bend lines 16, so as to provide a plurality of flat sidewall members 124 disposed at an acute angle to each other and meeting one another at an acute angle at the bend lines 16, as will be clearly apparent.

The second pair of sidewalls -14 are formed from flat stock cut to a zigzag configuration in their own planes, the zigzag configuration corresponding to that of the zigzag bent sidewalls 12 so that the two pairs of sidewalls may be welded or otherwise secured together along their contiguous edges.

It will be apparent that as the result of the configuration of the sidewalls l2, 14, the passage 15 has a zigzag tortuous form, so that when exhaust gases flow through the passage they successively encounter the sidewall members 12a at an acute angle and effective silencing of sound is obtained. it will be also noted that this is done without any internal baffles such as i are used in conventional mufflers, and since the sidewalls l2, 14 are fully exposed to the atmosphere, they are cooled by the ambient air and therefore are not subjected to premature damage by effects of heat.

The ends of the muffler are provided with tubular adapters 1-7 for installation of the muffler in the exhaust system, as between an exhaust pipe 18 and a tailpipe 19, the flow of exhaust gases through the tortuous passage 15 being indicated by the arrows 20. However, the pipe connections may just as well be reversed, since the muffler functions with equal efficiency with gas flow in either direction. The tubular adapters 17 may be welded to apertured end plates 21 which in turn are welded to the end edges of thesidewalls l2, 14.

The sound-attenuating characteristics of the muffler are related to the angle included between adjacent sidewall members 12a, and this angle may be selected so that the sound-attenuating properties are best suited for an engine of a given piston displacement. The preferred angle is of 60", which is suitable for an engine with a displacement of 231 cubic inches. For engines with a higher displacement the angle should be smaller, but in all instances the angle should be an acute angle in the broadest range of 45 to 75 and an intermediate range of 50 to 70, with preference at 60 as shown in FIG. 1. FIG. 4 shows a muffler wherein the included angle between the zigzags is this being outside of the angle range deemed appropriate for the invention, as stated above.

It is to be particularly noted that during fabrication of the muffler the end plates 21 with the adapters 17 may be secured to the pair of sidewalls l2 and before the sidewalls 14 are applied, the zigzag bent walls 12 may be compressed or extended to some extent, thereby correspondingly'varying the angular relationship of the sidewall members 12a. In this manner the sidewall members 12a may be prepositioned at a selected angle and the wall members 14 shaped accordingly before they are secured to the members 12, thus enabling fabrication of a muffler to suit the piston'displacement of a particular engine.

What I claim is:

l. A muffler comprising a first pair of spaced parallel sidewalls formed from straps which are zigzag bent along a plurality of longitudinally spaced transverse bend lines ,to provide a plurality of flat sidewall members disposed at an acute angle to each other and meeting one another at an acute angle at the bend lines, a second pair of spaced parallel sidewalls formed from flat sheet stock and having a zigzag configuration in their own flat planes, said second pair of walls being secured to opposite side edges of said first pair of walls and coacting therewith to define a zigzag tortuous passage of a rectangular cross section, and a pair of tubular adapters secured to the first and second pairs of walls at the opposite ends of said passage.

2. The device as defined in claim 1 which is further characterized in that the acute angle included between adjacent of said-sidewall members is between 45 and 75.

3. The device as defined in claim 1 which is further characterized in that the acute angle included between adjacent of 7 

1. A muffler comprising a first pair of spaced parallel sidewalls formed from straps which are zigzag bent along a plurality of longitudinally spaced transverse bend lines to provide a plurality of flat sidewall members disposed at an acute angle to each other and meeting one another at an acute angle at the bend lines, a second pair of spaced parallel sidewalls formed from flat sheet stock and having a zigzaG configuration in their own flat planes, said second pair of walls being secured to opposite side edges of said first pair of walls and coacting therewith to define a zigzag tortuous passage of a rectangular cross section, and a pair of tubular adapters secured to the first and second pairs of walls at the opposite ends of said passage.
 2. The device as defined in claim 1 which is further characterized in that the acute angle included between adjacent of said sidewall members is between 45* and 75*.
 3. The device as defined in claim 1 which is further characterized in that the acute angle included between adjacent of said sidewall members is between 50* and 70*.
 4. The device as defined in claim 1 which is further characterized in that the acute angle included between adjacent of said sidewall members has a magnitude of 60*.
 5. The device as defined in claim 1 which is further characterized in that the zigzag bent straps forming said first pair of sidewalls are compressively and extensively adjustable prior to securing of the second pair of sidewalls thereto, whereby said sidewall members may be prepositioned at a selected acute angle to one another. 